chore(rendering-changes): update 4.3.0 article with built-in dialogs

upgrade/rendering-changes/4-3-0.md

@@ -15,6 +15,7 @@ position: 1
 * [FlatColorPicker](#flatcolorpicker)
 * [MultiColumnComboBox](#multicolumncombobox)
 * [Slider](#slider)
+* [Built-in Dialogs](#built-in-dialogs)
 
 
 ## Icons
@@ -115,6 +116,15 @@ The 4.3.0 release brings about the following rendering changes for the Telerik U
 | `<a class="k-button-decrease">` | `<button class="k-button-decrease">` |
 | `<a class="k-button-increase">` | `<button class="k-button-increase">` |
 
+## Built-in Dialogs
+
+In an attempt to unify the look and feel of our components, the action buttons in all built-in dialogs(such as  now follow a common set of guidelines:
+
+* action buttons are now rendered inside a dedicated footer `<div class="k-actions">` element.
+* the confirmation button always precedes the cancelation one, when such is present.
+* when part of a non-resizable dialog, the action buttons are stretched. Such an example is the Filter or the Column Menu.
+
+Such dialogs are any edit forms, filter menus, column menus, editor's tools, as well as the TimePicker and DateTimePicker popups.
 
 ## See Also